STUDIES ON THE CYCLIC AMP RECEPTOR PROTEIN OF E COLI

CAMP受体蛋白(Crp)在分解代谢产物转录中起关键作用 可抑制操纵子通过cAMP依赖的DNA作为正调控因子 (启动子)结合。拟议的研究涉及对角色的调查 CAMP和DNA结合的C反应蛋白结构和功能。CRP有一个域 氨基近端区域参与结合cAMP和 当羧基近端区域参与亚基-亚基相互作用时 DNA结合。多肽片段和核心由有限的 C反应蛋白的蛋白分解；这些将与C反应蛋白的重建相关研究 体外紫胶酶的活性、DNA结合及其可能的调节特性 GAL操纵子的表达。C反应蛋白在羧基末端的修饰 将进行羧基肽酶的研究以确定该区域在DNA中的作用 结合和C反应蛋白构象。化学修饰研究将继续进行。 确定对C反应蛋白结构和功能的影响。一种温度敏感的C反应蛋白 突变体将被提纯，并根据ts损伤进行特征分析；回复突变体 将被选中进行研究，显示出与野生动物不同的特性 键入crp。利用杂交瘤制备抗C反应蛋白的单抗 碎片。这些单特异性抗体将被用作CRP的探针 构象和功能。

The cAMP receptor protein (CRP) plays a key role in transcription of catabolite repressible operons as a positive regulatory factor via cAMP dependent DNA (promoter) binding. The proposed research involves an investigation of the role of CRP structure and function for cAMP and DNA binding. CRP has a domain structure in which the amino proximal region is involved in binding cAMP and subunit-subunit interaction while the carboxyl proximal region is involved in DNA binding. Polypeptide fragments and cores have been generated by limited proteolysis of CRP; these will be studied with regard to reconstitution of CRP activity, DNA binding and possible regulatory properties for in vitro lac and gal operon expression. Modification of CRP at the carboxyl terminus by carboxypeptidase will be carried out to determine the role of this region in DNA binding and CRP conformation. Chemical modification studies will be continued to determine effects on CRP structure and function. A temperature sensitive CRP mutant will be purified and characterized in terms of the ts lesion; revertants will be selected for study which show properties different from that of wild type CRP. Using hybridomas monoclonal antibodies will be prepared against CRP fragments. These monospecific antibodies will be used as probes of CRP conformation and function.